1. Field of the Invention
The present invention relates to a stent delivery method and apparatus including a stent sheath within which the stent mounted on a balloon of a balloon catheter or BOAW is carried. The sheath is constructed in a special manner at its distal end to permit the stent and balloon to be moved out of the sheath distal end, particularly with ejection of a sheath softening fluid into the sheath.
2. Description of the Related Art Including Information Disclosed Under 37 CFR .sctn.1.97-1.99
Heretofore various stents, stent delivery methods and stent delivery apparatus have been proposed. Some examples of these previously proposed stent methods and apparatus are disclosed in the following U.S. patents:
______________________________________ U.S. Pat. No. Patentee ______________________________________ 4,140,126 Choudhury 4,503,569 Dotter 4,733,665 Palmaz 4,739,762 Palmaz 4,762,128 Rosenbluth 4,848,342 Kaltenbach 4,886,062 Wiktor 4,950,227 Savin et al. 5,019,090 Pinchuk 5,037,392 Hillstead 5,041,126 Gianturco 5,100,429 Sinofsky et al. 5,108,416 Ryan et al. 5,147,385 Beck et al. 5,158,548 Lau et al. 5,192,297 Hull 5,246,421 Saab ______________________________________
The Choudhury U.S. Pat. No. 4,140,126 discloses a method for performing aneurysm repair in which a prosthetic graft is carried by a catheter to a location of an aneurysm where it is anchored and the catheter is then removed.
The Dotter U.S. Pat. No. 4,503,569 discloses a transluminally placed expandable graft prosthesis which is inserted into a blood vessel in its unexpanded state and then expanded.
The Palmaz U.S. Pat. No. 4,733,665 and the Palmaz U.S. Pat. No. 4,739,762 disclose an expandable intraluminal graft and a method and apparatus for implanting the expandable intraluminal graft with an angioplasty balloon catheter. The graft can be a wire mesh tube or a thin welded tubular member having a plurality of longitudinal extending spaced slots which are parallel to the longitudinal axis of the tubular member.
The Rosenblurb U.S. Pat. No. 4,762,128 discloses a method and apparatus for treating hypertrophy of the prostate gland by inserting a stent with an expansion catheter.
The Kaltenbach U.S. Pat. No. 4,848,342 discloses a rotatable dilatation catheter that comprises a pressure member formed by a coil of wire having open turns which are expandable and which are situated adjacent a distal end of the catheter.
The Wiktor U.S. Pat. No. 4,886,062 discloses an intravascular radially expandable stent and method of implanting same in a blood vessel.
The Savin et al. U.S. Pat. No. 4,950,227 discloses a stent delivery system including a catheter having an expandable portion and a distal sleeve having a proximal margin overlying a distal margin of the stent in its unexpanded state and a proximal sleeve having a distal margin overlying a proximal margin of the stent in its unexpanded state.
The Pinchuk U.S. Pat. No. 5,019,090 discloses a radially expandable endoprosthesis (stent) and the like which is in a sheath having an open distal end. A cylindrical pusher is located within the sheath for pushing out the stent into an area of a lesion in a blood vessel. Alternatively, the stent can be mounted on a balloon of a balloon catheter for being delivered to the area of the lesion.
The Hillstead U.S. Pat. No. 5,037,392 discloses a stent-implanting balloon assembly which includes a balloon having three longitudinal creases whereby, where the balloon is in a deflated state the lateral extent in-cross-section of the balloon is less than the diameter of a stent received thereon.
The Gianturco U.S. Pat. No. 5,041,126 discloses an endovascular stent and delivery system including a balloon on a balloon catheter. The stent has a generally cylindrical envelope formed by a wire which extends in single circles back and forth between connecting loops in a continuous undulating pattern.
The Sinofsky et al. U.S. Pat. No. 5,100,429 discloses an endovascular stent and delivery system including a coiled stent of collagen-based material which is carried on a balloon of a balloon catheter to a stenosed region in an artery.
The Ryan et al. U.S. Pat. No. 5,108,416 discloses a stent introducer system including a stent received on a balloon of a balloon catheter and a stent retaining means located adjacent at least one end of the balloon for retaining the stent in position until the balloon is inflated, whereupon the stent retaining means releases the stent.
The Beck et al. U.S. Pat. No. 5,147,385 discloses a stent and catheter for the introduction of the stent. The stent is a hollow cylindrical structure which becomes plastic and malleable when heated, such as by heating the balloon.
The Lau et al. U.S. Pat. No. 5,158,548 and the Lau et al. U.S. Pat. No. 5,242,399 disclose a method and system for stent delivery including a sheath extending proximally from a coiled wire spring end of a guidewire in a generally conical manner to a generally cylindrical body that extends rearwardly a sufficient distance to cover a balloon of a balloon catheter received on the guidewire and to cover an expandable stent positioned on the balloon.
The Hull U.S. Pat. No. 5,192,297 discloses an apparatus and method for placement and implantation of a stent. A balloon catheter coaxially carries on a distal end portion thereof the radially expandable stent distally of the balloon of the balloon catheter. The catheter and stent are placed in a guiding catheter in such a way that the stent may emanate from the distal end of the guiding catheter for positioning in a vessel followed by the balloon which is then positioned within the stent and expanded.
The Saab U.S. Pat. No. 5,246,421 discloses a sheath through which a balloon dilatation catheter is moved.